Hyaline cartilage-origin bone and soft-tissue neoplasms: MR appearance and histologic correlation

Magnetic resonance (MR) images and histologic studies of 16 chondroid-matrix lesions were reviewed to determine if any distinctive morphologic or signal features might be discerned. Ten biopsy-proved nonchondroid bone lesions were compared in terms of configuration and signal characteristics. The tumor matrix had a distinctive appearance of homogeneous high signal intensity in a defined lobular configuration on images of all hyaline cartilage lesions obtained with a long repetition time and a long echo time. The areas of hyperintensity relative to muscle corresponded to areas of hyaline cartilage matrix with its uniform composition, low cellularity, and high water content; the lobular morphologic characteristic had an identical histologic correlate. The chondroblastomas, clear-cell chondrosarcoma, and synovial chondromatosis demonstrated a much more cellular stroma, with only scattered islands of chondroid matrix, and were isointense or hypointense compared with muscle on all MR sequences. The distinctive lobular, high-intensity MR appearance was not seen in the ten nonchondroid bone lesions.